its a choice you have to make I'm afraid as is so hard to tell if it is SF and if it is SF how he will be affected. With SF it may start mild but if your child is one of the unlucky ones they can deteriorate fast and then the tamiflu has less of a chance of owrking the longer you leave it. Am sure many of the people diagnosed don't have the SF though so the tamiflu is very over prescribed.
Personally (and I'm not giving advice)if we hadn't already had SF and my children were swabbed and I was told they had swine flu I would give them the tamiflu as I've seen how horrid SF can be and struggled fighting it off myself. The symptoms of the tamiflu are quite mild in most cases where as SF if it gets a hold of you can cause you serious health problems at it's worst. The issue is if you don't have SF you don't need it and it's hard to tell in the early stages whether it's SF or not and in many cases it won't be.
My girls had SF and tamiflu, my youngest I think could've fought it off herself maybe but my eldest had bad breathing problems and ended up in A&E so was really glad had rather reluctantly given it to her earlier that day, given her sudden decline.
The tamiflu is supposed to stop more serious conditions such as pneumonia developing and prevent other people in the house hold from being as likely to get the SF as the virus doesn't reporduce as much.
I swing between feeling so glad I got tamiflu for the girls and they fought of the SF so quickly, in particular my eldest who could hardly breathe and bounced back quickly, to panicing about if it will have any side effects.
I took tamiflu but think I was late taking it and I did have much more trouble shaking of the flu and did get a secondary infection and still have a lot of rib pain nearly 2 weeks on.
I've read people on here saying that they had 2 children 1 had tamiflu, 1 didn't and they both recovered the same though.
I'd read up on it yourself and make the decision you feel is right nobody can make that for you, it's such a shame they don't swab anymore would make our decision so much easier wouldn't it.
Hope he's better soon what ever it is x